The Role of Marshlands in the Current Water Management Framework

Marshland flooding dynamics – natural conditions

The extent of the flooded areas is subject to variability during the year, according to the hydrological regime. Dry years lead to a reduction of the flooded areas, while wet years contribute to an increase in the extent of the marshlands.

The marshlands’ natural inflow-outflow system strongly depends on the presence of flood peaks and, generally, on the hydrological regime of the rivers, that bring water to the marshlands. Before humans intervened in the hydraulic system, the area upstream of the marshlands was periodically inundated during floods. Conversely, during droughts, the extent of the inundated areas decreased, causing an alternation in the wetlands’ behaviour, and generally helping the development of biodiversity and optimizing environmental conditions: the variation of the flood extension and water depth create favourable conditions for flora and fauna. Moreover, man-made levees and embankments did not exist under natural conditions. Thus, there was less physical limitation to the extent of inundation, except for the natural levees and gradual changes in terrain elevation. Large flow peaks entered these wetlands and floods were naturally attenuated as water extended over the floodplain. Large volumes of water moving through the wetlands helped maintain a high level of connectivity between the various marshes and rivers.

Marshland flooding dynamics – current conditions

Nowadays, the marshes are managed completely differently: the presence of dams, man-made levees and embankments allows for full control of how water enters the marshes and where it flows. Dams and levees were built to enable and protect human activities. An immediate consequence of the construction of dams was the disappearance of peak flows from the rivers and the reduction of total available water for southern Iraq. At the same time, the construction of an extensive levee system imposed physical constraints on the amount of land potentially available for marshland development as well as the connectivity between marshlands and rivers.

In these conditions, marshes are no longer connected one to another, and if some connectivity still exists, it is only because the local population has breached the existing levees, or because a man-made canal brings water from one place to another.

The lack of peak flows and hydro-periods, the reduction in water availability and the lack of hydrological connectivity are all contributing to the existence of an unhealthy and unstable marshland system.This marshland flow management, which has been extensively applied in southern Iraq in the past decades, can be referred to as ‘semi-natural’: inflows to the marshes are fully controlled, whereas outflows are unmanaged, although not natural. Unfortunately, it is a losing strategy, as large flows are no longer guaranteed and flow variation inside the marshes cannot be mimicked without an adequate artificial system.

Recognizing that both ‘natural’ and ‘semi-natural’ management is no longer feasible or adequate, the Ministry of Water Resources is currently pursuing ‘controlled’ management, a system where both inflows and outflows are fully controlled. Controlled management attempts to attain the necessary flow-through and water-level variations required by the ecological system to thrive. From a hydraulic standpoint, controlled management operates by preventing or limiting the water flowing out from the inundated areas. It is not only a feasible option but also the most water-efficient.

From 2008 to 2010, the Ministry of Water Resources supervised the design of the hydraulic structures necessary for the controlled flooding of the marshlands. Some of these hydraulic structures have been constructed in the last five years, in particular the outlets of the Hawizeh and Central Marsh.

Benefits of marshland restoration

The government has acknowledged the importance of the marshlands for both environmental conservation and water resource management. This was expressed in e.g. the New Eden Master Plan in 2006-2008 and the SWLRI strategic plan in 2015. In addition, concrete actions have been taken, such as the approval on 23 July 2013 by the Iraqi Council of Ministers for the Central Marsh to be designated as the country’s first national park.

The marshes perform a variety of ecosystem services, including:

Hospitable environment that serves communities, and reduces the occurrence of migration from the marshes to urban centres;

Carbon sequestration, i.e. absorption of carbon dioxide (CO2) from the atmosphere by the vegetation growing in the marshes;

Flood hazard mitigation;

Production and sale of goods from the marshes, including dairy products from water buffalo, milk from cows, fish, reeds, etc.;

Groundwater recharge;

Water purification, i.e. wetlands naturally help to reduce pollutants because wetland plant species absorb some constituents in the marsh water;

Prevention of erosion, sand or dust storms and desertification;

Improved microclimate, including lowering local temperatures and increasing local humidity;

Improved soil structure through the rehydration and introduction of organic matter;

The New Eden Plan computed a valuation of the marshlands based on various ecosystem function parameters, including direct use value attributed to direct utilization of ecosystem services, and indirect use value attributed to indirect utilization of ecosystem services through the positive externalities that ecosystems provide. The computation[1] estimated the value of the marshes to be equivalent to $3.4 billion per year, if the marshes were restored to their full historical boundaries. This valuation amounts to approximately $3,370 per hectare of marshes per year.

An analysis of nearly 170 international inland wetlands indicates that the ecosystem services provided by these wetlands have an annual value ranging from $5,500 per hectare to approximately $110,000 per hectare. The average unit value of the surveyed inland wetlands in this analysis is $28,000 per hectare per year.[2] Thus, the estimation in the New Eden Plan is conservative compared with the international valuation of similar ecosystems. It should also be noted that even at this conservative valuation, the restoration of the marshes produces an economic return which is comparable to (if not higher than) agriculture for the governorates of southern Iraq.

[1] New Eden Group (2006). New Eden Master Plan for Integrated Water Resources Management in the Marshlands Area. Final report prepared for Iraq’s Ministries of Water Resources, Municipalities and Public Works, and Environment.[2] De Groot, R. et. al. (2012). ‘Global estimates of the value of ecosystems and their services in monetary units’. Ecosystem Services, 1: 50-61.